Hoya sp. EPC-209 hails from the Narathiwat Province of Southern Thailand.  I did a little research on what the climate is like in that area, and was shocked at just how warm and humid it is.  For every month of the year the temperature at night does not usually drop below 73°F and the daily average temperature is around 90° with humidity rarely dropping below 82%.  Talk about living in a pressure cooker!  Without my grow tents, I would have virtually no chance of ever flowering this species.